This invention relates to a bearing assembly and more particularly to elastomeric journal bearing assemblies which are adapted for marine propeller shafts. Elastomeric journal bearings have been found to be particularly suited for this purpose because of their exceptional ability to withstand the harmful effects of corrosive fluids and to abrasion resulting from bits of foreign materials which are carried in suspension in the sea water or other liquids in which the shaft and journal bearing assembly operates. Such elastomeric journal bearing assemblies have been made and are still being made with rigid metallic non-corrosive support members but these rigid metallic materials are more expensive and their corresponding manufacturing costs are higher. A further advantage of the elastomeric journal bearing is that since they operate in a liquid medium they are self lubricated and therefore highly desirable for marine use as for the stern propeller shaft journals.
The present invention provides a new and novel method for making an improved elastomeric journal bearing utilizing a novel outer shell and inner shell wherein the integral assembly provides a plurality of circumferentially spaced radially inwardly extending projections that provides support for the shaft and a plurality of water wedges for lubricating purposes rather than have the plural supports operate as squeegees which would wipe the lubricant off. The method employs a flat molding process that is combined with a winding process whereby a fiberglass reinforced rubber or elastomeric shell is further supported by a fiberglass reinforced plastic which provides a rigid outer housing for the inner flexible spaced supports. A unique advantage of the present invention is to materially reduce the cost of fabricating the fiberglass reinforced plastic inner supports of the bearing and to reduce the stock of inventory required to be carried to service the industry because of the versatility of the process. In addition, the outside diameter of the finished bearing can be machined to a desired diameter and additional layers of fiberglass reinforced plastic can be molded back onto the outer shell by a simple winding process to increase its dimensions to any desired size and thereafter stored for subsequent machining and use. This process is simple and can provide means for accurately sizing the outer diameter without the use of expensive molding processes. Applicant's process also permits the manufacture of a given size of flat strips of fiberglass-rubber reinforced sheets which can be stored and when needed can be cut to the desired size, wound and molded and then machined to the precise dimension. The cutting of the strips of fiberglass reinforced rubber to the desired sizes such as staves permits greater flexibility in the manufacturing process and eliminates the need for many size molds.